For nearly 2500 years, cases of typhoid fever have been documented around the world. From the epidemic’s origins in Greece, to its appearance in the industrializing United States, and finally to its current presence in underdeveloped nations, typhoid has become a problematic illness. The disease is easily prevented and well-treated, but in areas of the world that suffer from poor economies or unsanitary conditions, typhoid is a common occurrence and often leads to permanent health problems or death. In the past century, however, the creation of many antibiotics has enabled wealthy countries, like the United States, to combat the disease, and new medical technology has allowed these drugs to be reproduced for the masses.
Chloramphenicol, one of the first antibiotics used to treat typhoid fever, is one drug that is produced synthetically today. Because it is produced synthetically, chloramphenicol is readily available to under-developed nations who are in desperate need of a treatment for typhoid. The drug, however, has recently become controversial because of its dangerous side effects, which could result in the development of rare and untreatable illnesses such as leukemia and aplastic anemia. Due to the possibility of these very serious side effects, many underdeveloped countries have decided to cease the use of chloramphenicol to treat typhoid fever.
(An lanced opium poppy; morphine is its active ingredient –
http://www.rsc.org/ej/CC/2002/b111551k/b111551k-f1.gif)
Morphine is an alkaloid molecule, a term given to “natural occurring nitrogen-containing bases found mainly in plants” (NB 249). It is one of twenty-four such alkaloids found within the resin of the opium poppy plant – Papaver somniferum – and it usually comprises 10% of all opium extract.
Designated with the chemical formula C17H19NO3, morphine exists mainly as a “bitter, white crystalline compound” (C&E News), one that is water-insoluble. It has appeared and continues to appear in a variety of other forms, however, including, but not limited to: pharmaceutical concoctions (i.e. Patent medicines), morphine acetate (salt), morphine hydrochloride (salt), and morphine sulfate (salt).
Because of these possible physical forms, morphine has been both ingested and injected throughout history, all in attempt to exploit its wonderful analgesic and euphoric effects – properties unfortunately linked to physiological addiction. It is these consequences of consumption that make morphine both an incredibly important and intriguing molecule to study. A double-edged sword in every way, morphine has been both a bane and boon to human existence.
PBI’s use in the fire service has not been without its critics. Many older firefighters believe that the reason the number of firefighters killed each year is continuously rising is because of how good the gear works.
Back when firefighters only had a beard to protect their face, and a long rubber coat, it was rare to enter a burning building unless it was obvious that someone could be saved. Today with all the advances in gear, we go into buildings that we have no reason to go into and often stay in way to long. Before when you felt heat on your body it meant it was time to get out, today with PBI gear by the time you feel heat and pain, its too late, you’re going to get burnt or killed.
This is a fire in Susquehanna Township, outside of Harrisburg City. When we arrived on scene fire was blowing out of almost all the windows and all the floors. This picture was taken about 10 minutes into the operations when everything in the house had been destroyed. Todays modern firefighting practices, in no small part becuase of PBI, lead firefighters to these aggressive attacks. There was no one inside the house, and almost nothing to be saved, but we still made an agressive interrior attack. Several firefighters had minor injuries including Dickinson College Student Alex Hallman ’08 who fell from the top floor into the basement, he was not hurt.
The negative is not without the good. Had the firefighters tried to make an aggressive attack in the old style of gear they would not have been able to, and had there been someone inside many firefighters would have been burnt or worse.
This is a prime example of PBI gear allowing firefighters to “push the limit” and enter a structure they should not have entered. Another problem with PBI gear is that it works well to keep heat out, but also to keep heat in. Once the heat penetrates the suit, its in there and essentially cooks the person wearing it like they were in an oven. One way firefighters release the heat is by doing the “pain dance”. It looks like they are flapping little chicken wings, but it is meant to open up the neck of the suit allowing heat to be released and spread out, instead of just burning one area it makes a pins and needles feeling across the body, usually the back, chest and arms.
PBI is made through the combination of two chains, click on the image for a further explanation.
According to Wikipedia, the chemical formula of Poly[2,2’-(m-phenylen)-5,5’ bibenzimidazol] (PBI) is believed to be: ([NH-C=CH-C=CH-CH=C-N=C-]2-[C=CH-C=CH-CH=CH-])n OR (C20N4H12)n.
Because of its structure it has a high chemical and heat resistance which under “normal” conditions prevents it from burning or smoldering.
Its Heat resistance is:
continuous temperature: 540 °C (1,000 °F)
melting temperature: 760 °C (1,400 °F) under pyrolysis
retains fiber integrity and suppleness up to 540 °C (1,000 °F)
Another form of PBI called HOZOLE is being used for fuel cells and rockets because of its high resistance to heat. PBI can be both a “plastic” and a fabric, depending on the way which it is formed.
This is HOZOLE (It is the same as PBI).
The final product of PBI (in fire gear) allows firefighters to ender hazardous situations, risking their lives so others may live.
The worlds only producer of High Performance PBI fiber and polymer is PBI Performance Products Inc.
Their key product markets are protective clothing for the fire service and industrial workers, semiconductor and electronics, and various other high temperature applications.
History of PBI
1961 Polybenzimidazoles were developed by H. Vogel and C.S. Marvel with anticipation that the polymers would have exceptional thermal and oxidative stability.
1963 Subsequently, NASA and the Air Force Materials Lab sponsored considerable work with polybenimidazoles for aerospace and defense applications as a non-flammable and thermally stable textile fiber.
1969 The United States Air Force selects polybenzimidazole (PBI) for its superior thermal protective performance after a fire aboard an Apollo spacecraft killed three astronauts in 1967.
1970’s NASA continues to use PBI as part of the astronauts’ clothing on Apollo, Skylab and numerous space shuttle flights.
When the Sky lab fell to the earth, the part that survived the re-entry was coated in PBI and thus did not burn up.
1980’s PBI was introduced to the fire service, and through Project Fires an outer shell for turnout gear was developed. PBI Gold® fabric was born, consisting of 40% PBI/60% Para-aramid.
Previous to this there had been combinations of Nomex, Leather, and Kevlar materials.
Leather and Rubber fire gear left “vital” areas exposed.
PBI gear is a full suit and looks alot like a snow suit (suspender pants) with a winter coat.
1983 A unique production plant goes on-line and PBI fibers become commercially available.
1990’s Short cut PBI fibers are introduced for use in automotive braking systems. PBI staple fiber enters the aircraft market for seat fire blocking layers.
1992 Lightweight PBI fabrics are developed for flame resistant workwear for electric utility and petrochemical applications.
1994 PBI Gold fabric is engineered in black and was specified by FDNY.
2001 After the terrorist attacks on 9/11 many of the 343 Fire Fighters killed were only identifiable by their PBI Turnout Gear.
2003 PBI Matrix® was commercialized and introduced as the next generation PBI for firefighter turnout gear.
PBI replaced gear that was made of leather/rubber/or nomex. Nomex, leather and rubber are all still used but generally not without PBI. Some departments in more rural areas without the money to buy PBI turnout gear (about $2,500 per suit) still use the old style.
There are several major departments that have not yet switched to PBI becuase of tradition or fear of PBI and what happens with it. This picture is of the Chicago Fire Department, one of the last city departments to still rely on the old style of fire gear (3/4 length boots and 35″ leather or rubber coats) .
You can see in this picture that even with the boots pulled up some ‘vital’ areas are left unprotected.
What kind of environmental damages are the result of limestone and calcium carbonate quarrying?
Is it possible that the world can run out of concrete, with the copious amount of rock and aggregate?
The answer: Yes!
Many companies today are engaging in concrete recycling programs, which can keep the industry going strong without the detrimental factors involved with collecting rocks and chemicals needed for cement production, and the limited amount of some earthly materials, such as essential aggregages.
Another major aspect to the future of concrete is High Performance Concretes where special mixtures are invented using new technology that enhance the quality and versatility of the amazing substance. Everyday, scientists find new chemicals that supplant concrete’s strength, drying time, and stamina.
With Programs like these, The Future looks long and bright for CaCO3.
Pure Calcium Carbonate: The stuff that started it all!
Over the years, concrete has been responsible for a large amount of mishaps, due to the damage that can accumulate with its usage, such as cracks, fires, and chemical corrosion. Disaster can occur once a significant amount of damage is done. In this way, calcium carbonate affects history in a negative way, as it can destroy just as much as it can create.
Bacterial Damage – Bacteria can produce hydrogen sulfide, which oxidizes into the corrosive sulfuric acid, harming the surface of concrete. However, calcium carbonate in limestone can make the concrete more acid resistant.
Chemical Damage – The over use of substances that contain too much acid, such as sulfates, chlorates, and certain carbonates increase the pH of the concrete and can lead to cracking and dissolving. This is a serious issue with construction, as too much damage can cause a building to collapse.
Sea Water Damage – A particularly harmful effect on concrete structures is the erosion that occurs when it comes into contact with running water, such as bridges, where over the years, a bridge can collapse because of the amount of undersea damage sustained. Damage can be done to cars, people could get hurt, and traffic would be insane in an event such as this.
The Ugly sight of what can happen when concrete suspensions fail due to structural damage, built up over time.
Conclusion: Damage leads to disasters, disasters greatly affect history.
Mount Rushmore, near Keystone, ND, shows the great facades of our Presidents, comprised of almost complete granite, which is a rock that includes calcium carbonate deposits. The strong molecular structure of the rock alled for dynamite to blast through the stone cliff.
In 1984, The Statue of Liberty was closed so that a $62 million renovation could be performed. Concrete was a part of that renovation because in the places where the paint corroded the internal copper skeleton, and where steel was inappropriate to use, concrete was used to reinforce the areas. So in a way, CaCO3 was a part of the reason why the Lady is still standing today.
The Hoover Dam, the world’s largest complete concrete structure, is a $49 million dollar accomplishment that allows passage from Arizona to Nevada, holds back millions of gallons of water, and generates 2,080 megawatts of electrical power to hundreds of homes. Up to 10 million people visit each year. CaCO3 saves the day again.
Limestone, Limestone, Limestone
Even our own buildings on Dickinson College campus are lined with beautiful limestone, which is Calcium Carbonate.
The actual discovery of the molecule THC is very anti-climatic, the story is very similar to the discovery of opiates and other drugs
After realizing that morphine would attach to specific receptors in the brain, causing the sensation of being “high,” American and British organic chemists in the 1940s and the 1950s and found that there were specific receptors for THC in the brain and that the body produces a chemical similar to it, but there was little interest at this time so the research came to a halt.
In 1963 Mechoulam and Yehiel Gaoni were the first to isolate THC and reported the first synthesis of THC
From there, other organic chemists were able to to figure out the absolute configurations, which there are four of for THC.
In 1968 Mechoulam made book that talked all about his discovery and the Cannabinods found in the brain, he was able to make synthetic cannabinoid that was 100 times more potent then THC and was the key to finding the receptors in the brain
Today THC is used to help people with Cancer deal with pain and in now believed to help Alzeitmers
History of THC/Weed
10,000 BC- Traces of hemp rope have been found in China, these findings are the earliest use of cannabis
Chinese also used hemp cloth in burial rituals for the deceased and in medicine to help heal and take away pain
The Greeks began to use hemp in the around 600 BC
Egyptians in the Middle Ages, gardens of Cannabis were present through out the city of Cairo. Then the Egyptian government tried to ban the drug but was unable to do so because the use was reinforced by the Koran. The Koran explicitly banned the use of alcohol, but did not mention Cannabis
When Napoleon invade Egypt, he was amazed at the use of Cannabis and tried to uphold the ban. But when his soilders went back to France they told many stories of the amazing “hash” and its wonderful effects.
In the early 19th century Cannabis came to the United States, but was soon ban by the Federal Bureau of Narcotics because Harry J. Anslinger had a personal vendetta against the drug
But in the 1920s THC became a major product in medical research, then money ran out and laws were passed to stop the use of THC
After this the interest in THC research declined and the use of Marijuana declined, but in the early 20th century there was a rebirth, as immigrants moved into the US. There was a sudden surge in major cities, but Anslinger was determined to give THC a bad name by saying it corrupted the youth and provoked violent crimes.
In 1937 Marijuana was banned for good from further use in the United States
Now some states have made Marijuana legal or just legal for those who use it for medicine (see THC in the News)
